> the notion that desktop apps have a unified look and feel is a really recent phenomenon, that happened due to Apple, OS X and the iPhone.
The Apple HIG dates as far back as the Macintosh. That’s 1987[0]. Visual and behavioral consistency have always been a staple of good design for those who cared.
there is a certain section of third party app-developers that argue that app ux should absolutely emulate the host operating system. when this isn't sufficiently expressive, new interface elements should be designed such that they blend in naturally (ie, resemble what likely would have been the os-developer's choices).
